/**
 * Moondance UML modeling tool
 * 
 * This program is free software; you can redistribute it and
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package ro.pub.cs.se.moondance.model;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.draw2d.geometry.Dimension;
import org.eclipse.draw2d.geometry.Point;
import org.eclipse.jface.viewers.ICellEditorValidator;
import org.eclipse.swt.graphics.Image;
import org.eclipse.ui.views.properties.IPropertyDescriptor;
import org.eclipse.ui.views.properties.PropertyDescriptor;
import org.eclipse.ui.views.properties.TextPropertyDescriptor;

import ro.pub.cs.se.moondance.MoondancePlugin;

/**
 * Abstract prototype of an UML shape. Has a size (width and height), a location
 * (x and y position) and a list of incoming and outgoing connections. Use
 * subclasses to instantiate a specific shape.
 */
public abstract class UMLEntity extends ModelElement {
	private static final long serialVersionUID = 1;

	/**
	 * A static array of property descriptors. There is one IPropertyDescriptor
	 * entry per editable property.
	 * 
	 * @see #getPropertyDescriptors()
	 * @see #getPropertyValue(Object)
	 * @see #setPropertyValue(Object, Object)
	 */
	private static IPropertyDescriptor[] descriptors;

	/**
	 * ID for the Height property value (used for by the corresponding property
	 * descriptor).
	 */
	private static final String HEIGHT_PROP = "Shape.Height";

	/** Property ID to use when the location of this shape is modified. */
	public static final String LOCATION_PROP = "Shape.Location";

	/** Property ID to use then the size of this shape is modified. */
	public static final String SIZE_PROP = "Shape.Size";

	/** Property ID to use when the list of outgoing connections is modified. */
	public static final String SOURCE_CONNECTIONS_PROP = "Shape.SourceConn";

	/** Property ID to use when the list of incoming connections is modified. */
	public static final String TARGET_CONNECTIONS_PROP = "Shape.TargetConn";

	/**
	 * ID for the Width property value (used for by the corresponding property
	 * descriptor).
	 */
	private static final String WIDTH_PROP = "Shape.Width";

	/**
	 * ID for the X property value (used for by the corresponding property
	 * descriptor).
	 */
	private static final String XPOS_PROP = "Shape.xPos";

	/**
	 * ID for the Y property value (used for by the corresponding property
	 * descriptor).
	 */
	private static final String YPOS_PROP = "Shape.yPos";

	/*
	 * Initializes the property descriptors array.
	 * 
	 * @see #getPropertyDescriptors()
	 * 
	 * @see #getPropertyValue(Object)
	 * 
	 * @see #setPropertyValue(Object, Object)
	 */
	static {
		descriptors = new IPropertyDescriptor[] {
				new TextPropertyDescriptor(XPOS_PROP, "X"), // id and
				// description pair
				new TextPropertyDescriptor(YPOS_PROP, "Y"),
				new TextPropertyDescriptor(WIDTH_PROP, "Width"),
				new TextPropertyDescriptor(HEIGHT_PROP, "Height"), };
		// use a custom cell editor validator for all four array entries
		for (int i = 0; i < descriptors.length; i++) {
			((PropertyDescriptor) descriptors[i])
					.setValidator(new ICellEditorValidator() {
						public String isValid(Object value) {
							int intValue = -1;
							try {
								intValue = Integer.parseInt((String) value);
							} catch (NumberFormatException exc) {
								return "Not a number";
							}
							return (intValue >= 0) ? null
									: "Value must be >=  0";
						}
					});
		}
	}

	protected static Image createImage(String name) {
		InputStream stream = MoondancePlugin.class.getResourceAsStream(name);
		Image image = new Image(null, stream);
		try {
			stream.close();
		} catch (IOException ioe) {
		}
		return image;
	}

	/** Location of this shape. */
	private Point location = new Point(0, 0);

	/** Size of this shape. */
	private Dimension size = new Dimension(50, 50);

	/** List of outgoing Connections. */
	private List<Connection> sourceConnections = new ArrayList<Connection>();

	/** List of incoming Connections. */
	private List<Connection> targetConnections = new ArrayList<Connection>();

	/**
	 * Add an incoming or outgoing connection to this shape.
	 * 
	 * @param conn
	 *            a non-null connection instance
	 * @throws IllegalArgumentException
	 *             if the connection is null or has not distinct end points
	 */
	public void addConnection(Connection conn) {
		if (conn == null || conn.getSource() == conn.getTarget()) {
			throw new IllegalArgumentException();
		}
		if (conn.getSource() == this) {
			sourceConnections.add(conn);
			firePropertyChange(SOURCE_CONNECTIONS_PROP, null, conn);
		} else if (conn.getTarget() == this) {
			targetConnections.add(conn);
			firePropertyChange(TARGET_CONNECTIONS_PROP, null, conn);
		}
	}

	/**
	 * Return a pictogram (small icon) describing this model element. Children
	 * should override this method and return an appropriate Image.
	 * 
	 * @return a 16x16 Image or null
	 */
	public abstract Image getIcon();

	/**
	 * Return the Location of this shape.
	 * 
	 * @return a non-null location instance
	 */
	public Point getLocation() {
		return location.getCopy();
	}

	/**
	 * Returns an array of IPropertyDescriptors for this shape.
	 * <p>
	 * The returned array is used to fill the property view, when the edit-part
	 * corresponding to this model element is selected.
	 * </p>
	 * 
	 * @see #descriptors
	 * @see #getPropertyValue(Object)
	 * @see #setPropertyValue(Object, Object)
	 */
	public IPropertyDescriptor[] getPropertyDescriptors() {
		return descriptors;
	}

	/**
	 * Return the property value for the given propertyId, or null.
	 * <p>
	 * The property view uses the IDs from the IPropertyDescriptors array to
	 * obtain the value of the corresponding properties.
	 * </p>
	 * 
	 * @see #descriptors
	 * @see #getPropertyDescriptors()
	 */
	public Object getPropertyValue(Object propertyId) {
		if (XPOS_PROP.equals(propertyId))
			return Integer.toString(location.x);
		if (YPOS_PROP.equals(propertyId))
			return Integer.toString(location.y);
		if (HEIGHT_PROP.equals(propertyId))
			return Integer.toString(size.height);
		if (WIDTH_PROP.equals(propertyId))
			return Integer.toString(size.width);
		return super.getPropertyValue(propertyId);
	}

	/**
	 * Return the Size of this shape.
	 * 
	 * @return a non-null Dimension instance
	 */
	public Dimension getSize() {
		return size.getCopy();
	}

	/**
	 * Return a List of outgoing Connections.
	 */
	public List<Connection> getSourceConnections() {
		return new ArrayList<Connection>(sourceConnections);
	}

	/**
	 * Return a List of incoming Connections.
	 */
	public List<Connection> getTargetConnections() {
		return new ArrayList<Connection>(targetConnections);
	}

	/**
	 * Remove an incoming or outgoing connection from this shape.
	 * 
	 * @param conn
	 *            a non-null connection instance
	 * @throws IllegalArgumentException
	 *             if the parameter is null
	 */
	public void removeConnection(Connection conn) {
		if (conn == null) {
			throw new IllegalArgumentException();
		}
		if (conn.getSource() == this) {
			sourceConnections.remove(conn);
			firePropertyChange(SOURCE_CONNECTIONS_PROP, null, conn);
		} else if (conn.getTarget() == this) {
			targetConnections.remove(conn);
			firePropertyChange(TARGET_CONNECTIONS_PROP, null, conn);
		}
	}

	/**
	 * Set the Location of this shape.
	 * 
	 * @param newLocation
	 *            a non-null Point instance
	 * @throws IllegalArgumentException
	 *             if the parameter is null
	 */
	public void setLocation(Point newLocation) {
		if (newLocation == null)
			throw new IllegalArgumentException();
		location.setLocation(newLocation);
		firePropertyChange(LOCATION_PROP, null, location);
	}

	/**
	 * Set the property value for the given property id. If no matching id is
	 * found, the call is forwarded to the superclass.
	 * <p>
	 * The property view uses the IDs from the IPropertyDescriptors array to set
	 * the values of the corresponding properties.
	 * </p>
	 * 
	 * @see #descriptors
	 * @see #getPropertyDescriptors()
	 */
	public void setPropertyValue(Object propertyId, Object value) {
		if (XPOS_PROP.equals(propertyId))
			setLocation(new Point(Integer.parseInt((String) value), location.y));
		else if (YPOS_PROP.equals(propertyId))
			setLocation(new Point(location.x, Integer.parseInt((String) value)));
		else if (HEIGHT_PROP.equals(propertyId))
			setSize(new Dimension(size.width, Integer.parseInt((String) value)));
		else if (WIDTH_PROP.equals(propertyId))
			setSize(new Dimension(Integer.parseInt((String) value), size.height));
		else
			super.setPropertyValue(propertyId, value);
	}

	/**
	 * Set the Size of this shape. Will not modify the size if newSize is null.
	 * 
	 * @param newSize
	 *            a non-null Dimension instance or null
	 */
	public void setSize(Dimension newSize) {
		if (newSize != null) {
			size.setSize(newSize);
			firePropertyChange(SIZE_PROP, null, size);
		}
	}
}
